JP7182377B2 - coil spring - Google Patents

Description

The present invention relates to a coil spring that can be used as a valve spring for an internal combustion engine, a spring for a high-pressure pump, and the like.

A coil spring formed by forming a spring wire into a helical shape extending from one side to the other in the axial direction is widely used as a valve spring for an internal combustion engine, a spring for a high-pressure pump, and the like.

The coil spring is a member intended to exhibit elastic force along the axial direction when compressed in the axial direction. It is known to generate forces (lateral forces) in orthogonal directions as well.

It is desirable to prevent the generation of lateral force as much as possible.
That is, for example, when the coil spring is used as a pressing member for a reciprocating plunger, when a lateral force is generated, friction occurs between the plunger and a guide surface on which the plunger is reciprocally accommodated. power increases.
The increase in the frictional force causes wear due to the sliding resistance of the plunger and an increase in frictional heat, which may cause malfunctions in devices such as high-pressure pumps in which the plunger is used.

In this regard, the applicant of the present application has proposed a coil spring for the purpose of reducing lateral force (see Patent Documents 1 and 2 below).

The coil spring described in Patent Document 1 is configured so that the effective number of turns is an integer between the set height and the maximum use height, and the effective number of turns is not an integer or near an integer. In comparison, the lateral force generated during compression can be reduced.

In the coil spring described in Patent Document 2, the wire winding defined by the wire gap between spring wires adjacent in the axial direction is a first wire gap in which the wire gap is zero on one side in the axial direction. A first end region in which the line gap increases along the spiral shape from the zero point, and a line gap located on the other side of the first end region in the axial direction and having a line gap of a reference value L (L> 0) and a reference region located on the other side in the axial direction of the reference region, the gap between the wires narrowing along the spiral shape toward the other side in the axial direction, and the natural length at the zero point of the second gap between the wires. and a second end region in which the line-to-line gap is zero at the end position, wherein the first and second end regions have a line-to-line winding number exceeding 1 and a line-to-line distance in the natural length state at the end position is greater than L, and the winding between wires is provided between the terminal position of the first end region and the reference region, and spirals from the terminal position of the first end region to the other side in the axial direction A first transition region in which the line-to-line distance decreases as it progresses along the shape and reaches the reference value L, and the second end is provided between the end position of the second end region and the reference region. and a second transition region in which the line-to-line distance becomes smaller as it progresses along the spiral shape toward one side in the axial direction from the end position of the lower region and reaches the reference value L.

In the coil spring described in Patent Document 2, the gap between the wires in the first and second end regions gradually increases from zero toward the inner end and reaches the reference value L. Compared to the conventional coil spring constructed, it is possible to effectively suppress the generation of zero line clearance in the first and second end regions during compression operation, thereby reducing the generation of lateral force. It can be prevented.

As described above, the coil springs described in Patent Documents 1 and 2 can effectively prevent the generation of lateral force by their respective configurations, but there is room for improvement regarding the seat surface.

That is, the coil spring has a first seat surface on the first end turn portion on one side in the axial direction, and a second seat surface on the second end turn portion on the other side in the axial direction.

The first bearing surface is formed by grinding the axial outer surface of the first end turn portion so as to extend in a direction perpendicular to the axial direction of the coil spring. Similarly, the second bearing surface is formed by grinding the axial outer surface of the second end turn portion so as to extend in a direction orthogonal to the axial direction of the coil spring.

Here, in order to stabilize the posture of the coil spring during the compression operation and prevent the occurrence of lateral force, it is preferable to provide the first and second seating surfaces over at least half a circumference around the axis.

However, if the lengths around the axis of the first and second seat surfaces are simply increased, the thickness of the end portions of the first and second coil spring portions of the coil spring becomes thinner, and the first and second seat surfaces become thin. The rigidity of the end turn portion may decrease.

JP-A-2000-205320 JP 2017-190823 A

SUMMARY OF THE INVENTION It is an object of the present invention to provide a coil spring that can effectively prevent a decrease in rigidity at the end portion of the end turn portion while increasing the length of the seat surface around the axis. do.

In order to achieve the above object, a first aspect of the present invention provides a coil spring in which a spring wire is formed in a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction. The first seat has a first seat surface facing one side in the axial direction, and extends along the circumferential direction from the outer end portion forming the first end portion toward the inner end portion on the other side in the axial direction. A second seat having a winding portion and a second seat surface facing the other side in the axial direction, and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction. a winding portion, and a central winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion. and from the outer end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero The amount of displacement of the center position of the spring wire toward the other side in the axial direction up to the inner end is defined as the thickness of the spring wire, and then the first end turn portion is shifted from the outer end to the inner end. As it advances, the center position of the spring wire is gradually positioned on the other side in the axial direction, and the outer end portion of the first end turn portion and the outer end portion toward the inner end portion of the first end turn portion The amount of displacement of the center position of the spring wire to the other side in the axial direction between the point advanced by half the circumference is smaller than 1/4 of the thickness of the spring wire, and the outer side of the first end turn portion A circumferential movement amount of the spring wire moving along the circumferential direction from the end portion toward the inner end portion and an axis line of the center position of the spring wire toward the other axial direction side from the outer end portion of the first end turn portion The relationship between the amount of directional displacement is a curve that opens upward over the entire area from the outer end to the inner end of the end turn portion. To provide a coil spring having a shape which becomes larger as it progresses from the outer end to the inner end of a coil spring.

In order to achieve the above object, a second aspect of the present invention is a coil spring in which a spring wire is spirally formed from a first end on one side in the axial direction toward a second end on the other side in the axial direction. The first seat has a first seat surface facing one side in the axial direction, and extends along the circumferential direction from the outer end portion forming the first end portion toward the inner end portion on the other side in the axial direction. A second seat having a winding portion and a second seat surface facing the other side in the axial direction, and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction. a winding portion, and a central winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion. and from the outer end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero The amount of displacement of the center position of the spring wire toward the other side in the axial direction up to the inner end is defined as the thickness of the spring wire, and then the first end turn portion is shifted from the outer end to the inner end. As it advances, the center position of the spring wire is gradually positioned on the other side in the axial direction, and the outer end portion of the first end turn portion and the outer end portion toward the inner end portion of the first end turn portion The amount of displacement of the center position of the spring wire to the other side in the axial direction between the point advanced by half the circumference is smaller than 1/4 of the thickness of the spring wire, and the outer side of the first end turn portion A circumferential movement amount of the spring wire moving along the circumferential direction from the end portion toward the inner end portion and an axis line of the center position of the spring wire toward the other axial direction side from the outer end portion of the first end turn portion To provide a coil spring having a curvilinear shape that opens upward in relation to a directional displacement amount.

In the coil springs according to the first and second aspects of the present invention, the wire-to-wire windings defined by the wire-to-wire gaps between the axially adjacent spring wire rods are the one axial end of the central winding portion and the A first change in which the line gap increases as the line gap progresses along the circumferential direction from the first line gap zero point where the line gap is zero between the outer ends of the first end turn portion toward the other side in the axial direction. and a reference region located on the other side in the axial direction relative to the first changed region and extending along the circumferential direction toward the other side in the axial direction with the line-to-line gap remaining at the reference value, wherein the first changed region is , ends at a position of less than one turn in the circumferential direction from the zero point of the first inter-line gap at the axial outer end toward the other side in the axial direction, and the inter-line gap at the terminal end of the axial inner end is larger than the reference value. In the line-to-line winding, the winding is located between the first change area and the reference area, and extends from the terminal end of the first change area toward one end of the reference area in the axial direction. A first transition region is provided in which the line-to-line distance becomes smaller as it progresses in the circumferential direction and becomes a reference value.

In order to achieve the above object, a third aspect of the present invention provides a coil spring in which a spring wire is formed in a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction. The first seat has a first seat surface facing one side in the axial direction, and extends along the circumferential direction from the outer end portion forming the first end portion toward the inner end portion on the other side in the axial direction. A second seat having a winding portion and a second seat surface facing the other side in the axial direction, and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction. a winding portion, and a central winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion. and from the outer end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero The amount of displacement of the center position of the spring wire toward the other side in the axial direction up to the inner end is defined as the thickness of the spring wire, and then the first end turn portion is shifted from the outer end to the inner end. As it advances, the center position of the spring wire is gradually positioned on the other side in the axial direction, and the outer end portion of the first end turn portion and the outer end portion toward the inner end portion of the first end turn portion The amount of displacement of the center position of the spring wire to the other side in the axial direction between the point advanced by half the circumference is smaller than 1/4 of the thickness of the spring wire, and the outer side of the first end turn portion A circumferential movement amount of the spring wire moving along the circumferential direction from the end portion toward the inner end portion and an axis line of the center position of the spring wire toward the other axial direction side from the outer end portion of the first end turn portion The relationship with the amount of directional displacement is curved so that it opens upward, and the line gap between the end of the center winding portion on the other side in the axial direction and the outer end portion of the second end turn portion is zero. The amount of displacement to one side in the axial direction from the outer end to the inner end of the second end turn portion is defined as the thickness of the spring wire, and While the center position of the spring wire is gradually positioned on one side in the axial direction as it progresses toward the end portion, the outer end portion of the second end turn portion and the inner end of the second end turn portion from the outer end portion The amount of displacement of the center position of the spring wire toward the one side in the axial direction between the point half the circumference toward the second seat is set to be smaller than 1/4 of the thickness of the spring wire, and A circumferential movement amount of the spring wire moving along the circumferential direction from the outer end to the inner end of the winding portion, and a movement of the spring wire from the outer end of the second end turn portion to one side in the axial direction. Relationship with axial displacement of center position is a curve that opens downward over the entire area from the outer end to the inner end of the second end turn portion, and the curve is such that the slope of the tangent to the curve is that of the second end turn portion. To provide a coil spring having a shape that increases in size from an outer end to an inner end.

In order to achieve the above object, a fourth aspect of the present invention provides a coil spring in which a spring wire is formed in a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction. The first seat has a first seat surface facing one side in the axial direction, and extends along the circumferential direction from the outer end portion forming the first end portion toward the inner end portion on the other side in the axial direction. A second seat having a winding portion and a second seat surface facing the other side in the axial direction, and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction. a winding portion, and a central winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion. and from the outer end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero The amount of displacement of the center position of the spring wire toward the other side in the axial direction up to the inner end is defined as the thickness of the spring wire, and then the first end turn portion is shifted from the outer end to the inner end. As it advances, the center position of the spring wire is gradually positioned on the other side in the axial direction, and the outer end portion of the first end turn portion and the outer end portion toward the inner end portion of the first end turn portion The amount of displacement of the center position of the spring wire to the other side in the axial direction between the point advanced by half the circumference is smaller than 1/4 of the thickness of the spring wire, and the outer side of the first end turn portion A circumferential movement amount of the spring wire moving along the circumferential direction from the end portion toward the inner end portion and an axis line of the center position of the spring wire toward the other axial direction side from the outer end portion of the first end turn portion The relationship with the amount of directional displacement is curved so that it opens upward, and the line gap between the end of the center winding portion on the other side in the axial direction and the outer end portion of the second end turn portion is zero. The amount of displacement of the center position of the spring wire to one side in the axial direction between the outer end portion and the inner end portion of the second end turn portion is defined as the thickness of the spring wire, and the second end turn As the spring wire advances from the outer end to the inner end of the portion, the center position of the spring wire is gradually positioned on one side in the axial direction, and the outer end of the second end turn portion and the second coil from the outer end. The amount of displacement of the center position of the spring wire toward one side in the axial direction between the point advanced halfway toward the inner end of the two end turns is set to be smaller than 1/4 of the thickness of the spring wire. and one of the amount of circumferential movement of the spring wire moving along the circumferential direction from the outer end portion of the second end turn portion toward the inner end portion and the axial direction direction from the outer end portion of the second end turn portion Center position of the spring wire to the side To provide a coil spring having a curved shape that opens downward in relation to the amount of axial displacement of a device.

In the coil springs according to the third and fourth aspects of the present invention, the wire-to-wire windings defined by the wire-to-wire gaps between the spring wires adjacent in the axial direction are the one end portion in the axial direction of the central winding portion and the A first change in which the line gap increases as the line gap progresses along the circumferential direction from the first line gap zero point where the line gap is zero between the outer ends of the first end turn portion toward the other side in the axial direction. a reference region located on the other side in the axial direction of the first change region and extending along the other side in the axial direction with the line-to-line gap remaining at the reference value; and the other side of the reference region in the axial direction. a second changing region located on the other side of the axial direction and ending at a second zero point of the inter-line gap where the inter-line gap becomes zero as the inter-line gap becomes smaller as it progresses along the circumferential direction to the other side in the axial direction; The first change region ends at a position of less than one turn in the circumferential direction from the zero point of the first gap between lines at the outer end in the axial direction to the other side in the axial direction, and the gap at the end of the inner end in the axial direction is The second change region ends at a position less than one turn in the circumferential direction from the zero point of the second gap between the wires at the axial outer end to one side in the axial direction, and extends along the axial direction. The inter-line gap at the end of the inner end in the direction is configured to be larger than a reference value, and the inter-line winding is positioned between the first change area and the reference area and has a gap in the first change area. Between a first transition region in which the line-to-line distance decreases as it progresses in the circumferential direction from the terminal end toward one end in the axial direction of the reference region and becomes a reference value, the second change region, and the reference region A second transition region is provided in which the line-to-line distance becomes smaller as it progresses in the circumferential direction from the terminal end of the second change region toward the end of the reference region on the other side in the axial direction and becomes a reference value.

According to the present invention, a first end turn portion having a first seat surface, a second end turn portion having a second seat surface, and a center turn portion connecting between the first and second end turn portions. In the coil spring comprising The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the end and the inner end is defined as the thickness of the spring wire, and the thickness of the first end turn portion is changed from the outer end to the inner end. While the center position of the spring wire is gradually displaced to the other side in the axial direction as it advances toward the portion, the outer end portion of the first end turn portion and the inner end portion of the first end turn portion from the outer end portion The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the point advanced by half a turn toward the point is smaller than 1/4 of the thickness of the spring wire, and the first end turn portion and the center position of the spring wire toward the other side in the axial direction from the outer end of the first end turn portion. The first end turn portion is configured such that the relationship between the axial direction displacement amount of and/or the axial direction other end of the center turn portion and the second end turn is formed in a curved shape that opens upward. Displacement of the center position of the spring wire to one side in the axial direction between the outer end and the inner end of the second end turn so that the wire gap between the outer ends of the windings is zero. The amount is the thickness of the spring wire, and the center position of the spring wire is gradually positioned on one side in the axial direction as it progresses from the outer end to the inner end of the second end turn portion, A center position of the spring wire on one side in the axial direction between the outer end of the second end turn portion and a point proceeding from the outer end portion toward the inner end portion of the second end turn portion by half a circumference. is smaller than 1/4 of the thickness of the spring wire, and the spring wire progresses along the circumferential direction from the outer end toward the inner end of the second end turn portion. so that the relationship between the amount and the amount of axial displacement of the center position of the spring wire toward one side in the axial direction from the outer end of the second end turn portion becomes a curved line that opens downward. Therefore, even if the first bearing surface is provided over at least half the circumference around the axis, the thickness of the end portion of the first end turn portion is secured, and the rigidity of the first end turn portion is reduced. and/or, even if the second bearing surface is provided over at least half the circumference around the axis, the thickness of the end of the second end turn portion is secured and the second end turn portion Go It is possible to effectively prevent deterioration of the properties.

In addition, according to the present invention, the first end turn portion is formed such that the line gap between the one axial end portion of the central end turn portion and the outer end portion of the first end turn portion is zero. The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the outer end and the inner end is defined as the thickness of the spring wire, and the thickness of the spring wire is defined as the thickness of the spring wire. While the center position of the spring wire is gradually positioned on the other side in the axial direction as it progresses toward the end portion, the outer end portion of the first end turn portion and the inner end of the first end turn portion from the outer end portion The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the point advanced by half the circumference toward the part is smaller than 1/4 of the thickness of the spring wire, and the first end turn The amount of circumferential movement of the spring wire moving along the circumferential direction from the outer end to the inner end of the first end turn portion and the center of the spring wire from the outer end of the first end turn portion to the other side in the axial direction The relationship between the position and the amount of displacement in the axial direction is a curve that opens upward over the entire area from the outer end to the inner end of the end turn portion, and the curve has a slope of a tangent to the curve. and/or between the end of the center turn on the other side in the axial direction and the outer end of the second end turn. The amount of displacement of the center position of the spring wire to one side in the axial direction between the outer end portion and the inner end portion of the second end turn portion is defined as the thickness of the spring wire so that the gap between the wires is zero. In addition, the center position of the spring wire rod is gradually positioned on one side in the axial direction as it progresses from the outer end portion toward the inner end portion of the second end turn portion, and the outer end of the second end turn portion The amount of displacement of the center position of the spring wire to one side in the axial direction between the outer end and the point half the circumference from the outer end toward the inner end of the second end turn is the thickness of the spring wire and the amount of circumferential movement of the spring wire that progresses along the circumferential direction from the outer end to the inner end of the second end turn and the second end turn The relationship between the amount of displacement in the axial direction of the center position of the spring wire from the outer end of the second end turn portion to the one side in the axial direction is downward over the entire area from the outer end to the inner end of the second end turn portion The curve has a shape in which the slope of the tangent to the curve increases from the outer end to the inner end of the second end turn portion. and/ Alternatively, even if the second seat surface is provided over at least half the circumference around the axis, the thickness of the end portion of the second end turn portion can be ensured to effectively prevent reduction in rigidity of the second end turn portion.

In addition, according to the present invention, the first end turn portion is formed such that the line gap between the one axial end portion of the central end turn portion and the outer end portion of the first end turn portion is zero. The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the outer end and the inner end is defined as the thickness of the spring wire, and the thickness of the spring wire is defined as the thickness of the spring wire. While the center position of the spring wire is gradually positioned on the other side in the axial direction as it progresses toward the end portion, the outer end portion of the first end turn portion and the inner end of the first end turn portion from the outer end portion The amount of displacement of the center position of the spring wire toward the other side in the axial direction between the point advanced by half the circumference toward the part is smaller than 1/4 of the thickness of the spring wire, and the first seat A circumferential movement amount of the spring wire moving along the circumferential direction from the outer end to the inner end of the winding portion, and a movement of the spring wire from the outer end of the first end turn portion to the other side in the axial direction. The relationship between the center position and the amount of displacement in the axial direction is curved upward, and/or the line between the end of the center winding portion on the other side in the axial direction and the outer end portion of the second end winding portion. The amount of displacement of the center position of the spring wire toward one side in the axial direction between the outer end portion and the inner end portion of the second end turn portion is defined as the thickness of the spring wire so that the gap is zero. Above, the outer end portion of the second end turn portion while the center position of the spring wire is gradually positioned on one side in the axial direction as it progresses from the outer end portion toward the inner end portion of the second end turn portion. The amount of displacement of the center position of the spring wire to one side in the axial direction between the outer end and the point half the circumference toward the inner end of the second end turn portion is the thickness of the spring wire A circumferential movement amount of the spring wire which is smaller than 1/4 and which advances along the circumferential direction from the outer end portion to the inner end portion of the second end turn portion and the second end turn portion. Since the relationship between the amount of displacement in the axial direction of the center position of the spring wire from the outer end portion to one side in the axial direction is a curved line that opens downward, the first bearing surface extends over at least half the circumference around the axis. Even if the end portion of the first end turn portion is provided with a Even if it is provided over the entire length, the thickness of the end portion of the second end turn portion can be ensured to effectively prevent deterioration of the rigidity of the second end turn portion.

FIG. 1 is a front view of a coil spring in a natural length state according to one embodiment of the present invention. FIG. 2 is an upper perspective view of the coil spring in a natural length state. FIG. 3 is a bottom perspective view of the coil spring in a natural length state. FIG. 4 is a plan view of the coil spring in a natural length state. FIG. 5 is a bottom view of the coil spring in a natural length state. FIG. 6 is a graph showing the relationship between the number of turns of the coil spring and the amount of displacement in the axial direction. FIG. 7 shows the relationship between the number of turns and the amount of axial displacement in the coil spring. 8 is an enlarged view of the VIII part in FIG. 6. FIG. FIG. 9 is a graph showing the relationship between the number of turns between wires and the gap between wires in the coil spring. FIG. 10 is a schematic diagram of the apparatus for manufacturing the coil spring.

An embodiment of a coil spring according to the present invention will be described below with reference to the accompanying drawings.
1 to 5 show a front view, an upper perspective view, a lower perspective view, a plan view, and a bottom view, respectively, of the coil spring 1 according to this embodiment in its natural length state.

As shown in FIGS. 1 to 5, the coil spring 1 according to the present embodiment includes a spring wire 100 extending from a first end 101 on one axial side D1 toward a second end 102 on the other axial side D2. is formed into a helical shape, and is suitably used for valve springs of internal combustion engines, springs for high-pressure pumps, and the like.
In the coil spring 1 according to the present embodiment, the spring wire 100 has a circular cross-section, but spring wires with various cross-sectional shapes such as an elliptical cross-section or a rectangular cross-section can be used.

As shown in FIG. 1 and the like, the coil spring 1 includes a first end turn portion 10 extending along the circumferential direction from an outer end portion 11 forming the first end portion 101 toward the other axial direction side D2, A second end turn portion 20 extending along the circumferential direction from an outer end portion 21 forming the second end portion 102 toward one axial direction side D1, and an axial inner end portion 12 of the first end turn portion 10. and a center winding portion 30 spirally extending along the circumferential direction from the center winding portion 30 toward the other axial side D2 and connected to the axial inner end portion 22 of the second end winding portion 20 .

FIG. 6 shows a graph representing the relationship between the number of turns of the coil spring 1 and the amount of displacement in the axial direction.
As shown in FIG. 6 , the coil spring 1 according to the present embodiment has six turns including the first end turn portion 10 , the central end turn portion 30 and the second end turn portion 20 .

Specifically, the position of the number of turns "0" corresponds to the first end portion 101, and the area from the position of the number of turns "0" to the position of the number of turns "1" corresponds to the first end turn portion 10. .
Further, the position of the number of turns "6" corresponds to the second end portion 102, and the area between the position of the number of turns "5" and the position of the number of turns "6" corresponds to the second end winding portion 20. The central winding portion 30 corresponds to the position from the position of the number of turns "1" to the position of the number of turns "5".

As shown in FIGS. 1 and 6, the first end turn portion 10 is displaced from the axial outer end portion 11 to the axial inner end portion 12 toward the other axial side D2 by the thickness a of the spring wire 100. , the line-to-line gap between the axially outer end portion 11 and the end portion 31 of the center winding portion 30 on the one axial side D1 is zero.

Similarly, the second end turn portion 20 is displaced from the axially outer end portion 21 to the axially inner end portion 22 toward the axial direction one side D1 by the thickness a of the spring wire material. 21 and the end portion 32 of the center winding portion 30 on the other side D2 in the axial direction is zero.

Each of the first and second end turn portions 10 and 20 has an axially outer coil formed perpendicular to the axial direction of the coil spring 1 by polishing the surface on the axially outer side. Facing first and second seating surfaces 15, 25 are provided.

The first and second seating surfaces 15 and 25 form mounting surfaces for the coil spring 1 . Therefore, in order to stabilize the posture of the coil spring 1 and effectively prevent the lateral force from being generated during the compression operation of the coil spring 1, the first and second seat surfaces 15 and 25 must be: It is preferable to provide at least a half circumference of the coil spring 1 around its axis in a state orthogonal to the axial direction of the coil spring 1 .

However, when the first and second seating surfaces 15 and 25 perpendicular to the axial direction of the coil spring 1 are expanded around the axis of the coil spring 1, the first and second end turn portions 10, The thickness of the spring wire 100 at the outer ends 11, 21 of the coil spring 20 in the axial direction becomes thin, and as a result, the rigidity of the first and second end turn portions 10, 20 is reduced, and the lateral movement of the coil spring 1 during the compression operation is caused. force will be generated.

Regarding this point, the coil spring 1 according to the present embodiment is provided with the following configuration so that the first and second bearing surfaces 15, 25 extend more than half the circumference (specifically, as shown in FIGS. 3 and 4, , about 3/4 of the circumference of the coil spring 1), effectively preventing a decrease in rigidity of the first end turn portion 10 (and/or the second end turn portion 20), and laterally It effectively prevents the generation of force.

FIG. 7 shows the relationship between the number of turns and the amount of displacement in the axial direction in this embodiment.
FIG. 7 also shows the relationship between the number of turns and the amount of displacement in the axial direction in the modified example of the present embodiment and the conventional example.

As shown in FIG. 7, in the conventional coil spring, the number of turns is "0" (the position corresponding to the outer end portion 11 of the first end turn portion 10) and the number of turns is "1" (the position of the first end turn portion 10). The amount of displacement in the axial direction between the positions corresponding to the inner ends) is configured to change at a constant rate of inclination a, where a is the thickness of the spring wire.

That is, in the conventional coil spring, the amount of displacement in the axial direction is a/4 at the position of the number of turns "1/4", and the position of the number of turns "1/2" (outer end of the first end turn portion 10) At the position corresponding to the portion 11 and the position corresponding to the inner end portion 12 by half the circumference), the amount of displacement in the axial direction is a/2.

On the other hand, in the coil spring 1 according to the present embodiment, the outer end portion 11 in the axial direction of the first end turn portion 10 advances from the outer end portion 11 toward the inner end portion 12 in the circumferential direction by half a turn. The amount of axial displacement between the spring wire rod 100 and the piercing point is set to be less than half the thickness a of the spring wire 100 .

According to the coil spring 1 having such a configuration, even if the first bearing surface 15 is provided over half the circumference around the axis, the thickness of the outer end portion 11 of the first end turn portion 10 is equal to that of the spring wire rod. 1/2 or more of the thickness of 100 can be ensured, whereby the rigidity of the first end turn portion 10 can be effectively ensured.

As shown in FIGS. 1 and 7, in the coil spring 1, a first inflection point C1 (in the present embodiment, the number of turns " 3/4" point), the displacement in the axial direction is substantially zero, and from the first inflection point C1 to the inner end portion 12 of the first end turn portion 10 (the point where the number of turns is "1"). ) in the axial direction by an amount corresponding to the thickness a of the spring wire 100 .

According to such a configuration, even if the first seating surface 15 is provided over 3/4 of the circumference, the thickness of the outer end portion 11 of the first end turn portion 10 can be ensured to be a/2 or more. can.

FIG. 8 shows an enlarged view of the VIII section in FIG.
FIG. 8 also shows the relationship between the number of turns and the amount of displacement in the axial direction in the modified example of the present embodiment and the conventional example.

As shown in FIG. 8, for the second end turn portion 20, similarly, a second inflection point C2 ( In the present embodiment, the displacement in the axial direction is substantially zero between the outer end portion 21 of the second end turn portion 20 and the point 3/4 of the circumference toward one side in the axial direction, and the second displacement is substantially zero. It is configured to be displaced in the axial direction by an amount corresponding to the thickness a of the spring wire 100 between the bending point C2 and the inner end portion 22 of the second end turn portion 20 .

According to such a configuration, even if the second seat surface 25 is provided over 3/4 of the circumference, the thickness of the outer end portion 21 of the second end turn portion 20 can be ensured to be a/2 or more. can.

Instead of this, as in a modification shown in FIG. the first end turn portion 10 so that the amount of displacement in the axial direction between the end portion 11 and the inner end portion 12 is less than half the thickness a of the spring wire rod 100. so that the amount of circumferential movement traveling along the circumferential direction from the outer end portion 11 toward the inner end portion 12 of the second It is also possible to form one end turn portion 10 .

8, the second end turn portion 20 is located between the inner end portion 22 and a position that is half the circumference from the inner end portion 22 toward the outer end portion 21 in the circumferential direction. The amount of circumferential movement and the amount of movement along the circumferential direction from the inner end portion 22 toward the outer end portion 21 so that the amount of displacement to the other side in the axial direction is larger than half of the thickness a of the spring wire material and the axial direction The displacement amount on the other side is configured to form a curve that opens downward (that is, when the outer end portion 21 of the second end turn portion 20 is expressed as a reference point, the outer end portion 21 of the second end turn portion 20 is formed. so that the amount of displacement on one side in the axial direction between the end portion 21 and the position that is half the circumference in the circumferential direction from the outer end portion 21 toward the inner end portion 22 is smaller than half the thickness a of the spring wire 100, A curved relationship between the amount of circumferential movement traveling along the circumferential direction from the outer end portion 21 to the inner end portion 22 of the second end turn portion 20 and the amount of axial displacement toward one side in the axial direction. The second end turn portion 20 is configured such that
Such a modified example can also provide the same effects as in the present embodiment.

In the coil spring 1 according to the present embodiment, the outer end portion 11 of the first end turn portion 10 and the outer end portion 21 of the second end turn portion 20 are aligned in the circumferential direction. This also effectively prevents the generation of lateral force in the compression operation.

Further, the coil spring 1 according to the present embodiment has the following configuration with respect to inter-wire windings defined by the inter-wire gaps between the spring wires 100 adjacent in the axial direction.
FIG. 9 shows a graph representing the relationship between the number of windings between wires and the gap between wires in the coil spring 1. As shown in FIG.
Note that the number of windings between lines "0" to "5" shown in FIG. 9 corresponds to windings "1" to "6" shown in FIG.

Specifically, as shown in FIGS. 1 to 3, 5, and 9, the coil spring 1 has the wire-to-wire winding formed by the end portion 31 of the central winding portion 30 on one side in the axial direction and the first seat. A first change in which the line gap increases along the circumferential direction from the first line gap zero point 60a where the line gap is zero between the outer ends 11 of the winding portion 10 toward the other axial direction side D2. a region 61, a reference region 65 located on the other side D2 in the axial direction of the first change region 61 and extending along the circumferential direction toward the other side D2 in the axial direction with the line-to-line gap remaining at the reference value L; A second zero line gap point 60b is located on the other axial side D2 of the region 65, and the line gap becomes zero as it progresses toward the other axial side D2 along the circumferential direction. and a second transition region 69 terminating.

As shown in FIG. 9, in the coil spring 1 according to the present embodiment, the first changing region 61 extends circumferentially by 1 from the first wire gap zero point 60a at the axial outer end to the other axial direction side D2. The wire gap ends at a position less than the turn and the wire gap at the terminal end of the axial inner end is made larger than the reference value L, and the second change region 69 is the second wire gap zero point 60b at the axial outer end. from the one side D1 in the axial direction to end at a position of less than one turn in the circumferential direction, and the gap between the wires at the end of the inner end in the axial direction is larger than the reference value L, and further, the winding between the wires is Positioned between the first change region 61 and the reference region 65, the line-to-line distance extends in the circumferential direction from the terminal end of the first change region 61 toward the end of the reference region 65 on one side D1 in the axial direction. is located between the second transition region 69 and the reference region 65, and the second transition region 63 is positioned between the end of the second transition region 69 and the reference region 65 in the axial direction of the reference region 65. It is configured to have a second transition region 67 where the line-to-line distance decreases toward the end of the side D2 in the circumferential direction and reaches the reference value L. As shown in FIG.

With such a configuration, when the coil spring 1 is compressed from its natural length state, it is possible to effectively prevent the line gap from occurring in the first and second changing regions 61 and 69, thereby improving the compression operation. It is possible to effectively suppress the occurrence of lateral force.

That is, in the coil spring 1, the line-to-line distance at the ends (inner ends in the axial direction) of the first and second changing regions 61 and 69 located on both end sides in the axial direction is made larger than the reference value L. ing.
Therefore, it is possible to effectively prevent the adjacent spring wire rods 100 from unexpectedly coming into contact with each other on the one side D1 and the other side D2 in the axial direction due to the compression operation of the coil spring 1 and causing a change in the effective number of turns. As a result, it is possible to effectively suppress the generation of lateral force during the compression operation.

The coil spring 1 is manufactured, for example, by a manufacturing apparatus 200 shown in FIG.
As shown in FIG. 10, the manufacturing apparatus 200 includes a supply roller 210 that supplies the spring wire 100, a guide member 215 that guides the spring wire 100 conveyed by the supply roller 210, and a guide member 215 that guides the spring wire 100. First and second coiling tools 220 ( 1 ) provided downstream in the conveying direction of the spring wire 100 conveyed by the supply roller 210 in a folded state, for forming the straight spring wire 100 into the helical coil spring 1 . , 220(2), a core metal member 225 for guiding the coil spring 1 spirally formed by the first and second coiling tools 220(1), 220(2), and a pitch of the coil spring 1. It has a pitch tool 230 for adjustment and a cutting tool 235 for cutting the spring wire 100 in cooperation with the core bar 225 .

The first and second coiling tools 220(1) and 220(2) are adjustable in position in the radial direction with the center of the coil spring 1 to be formed as a reference. The coil diameter of the coil spring 1 is changed.

The pitch tool 230 is adjustable in position in the radial direction with the center of the coil spring 1 as a reference, and changes the pitch of the coil spring 1 according to the change in the radial position.

The cutting tool 235 is capable of reciprocating in the radial direction with respect to the center of the coil spring 1, and cuts the spring wire 100 in cooperation with the engaging surface 226 of the core metal 225. It is movable between a retracted position spaced apart from the core metal 225 .

1 coil spring 10 first end turn 11 outer end 12 of first end turn inner end 20 second end turn 21 outer end 22 of second end turn center winding portion 31 one axial end portion 32 of the central winding portion another axial end portion 60a of the central winding portion first zero point between the gaps 60b second zero point between the gaps 61 First change area 63 First transition area 65 Reference area 67 Second transition area 69 Second change area 100 Spring wire 101 First end 102 Second end C1 First inflection point C2 Second inflection point D1 Axial direction One side D2 Other side in axial direction

Claims (6)

A coil spring formed by forming a spring wire into a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction,
a first end turn portion having a first bearing surface facing one side in the axial direction and extending along the circumferential direction from an outer end portion forming the first end portion toward an inner end portion on the other side in the axial direction; a second end turn portion having a second bearing surface facing the other side in the axial direction and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction; a center winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion;
from the outer end to the inner end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the While the center position of the spring wire is gradually positioned on the other side in the axial direction, the outer end portion of the first end turn portion advances from the outer end portion toward the inner end portion of the first end turn portion by half a turn. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the first end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward the other side in the axial direction from the outer end portion of the first end turn portion is a curve that opens upward over the entire area from the outer end to the inner end of the end turn portion,
The coil spring, wherein the curve has a shape in which a slope of a tangent line to the curve increases as it progresses from the outer end portion to the inner end portion of the end turn portion. A coil spring formed by forming a spring wire into a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction,
a first end turn portion having a first bearing surface facing one side in the axial direction and extending along the circumferential direction from an outer end portion forming the first end portion toward an inner end portion on the other side in the axial direction; a second end turn portion having a second bearing surface facing the other side in the axial direction and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction; a center winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion;
from the outer end to the inner end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the While the center position of the spring wire is gradually positioned on the other side in the axial direction, the outer end portion of the first end turn portion advances from the outer end portion toward the inner end portion of the first end turn portion by half a turn. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the first end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward the other side in the axial direction from the outer end portion of the first end turn portion A coil spring characterized in that the relationship between is a curved shape that opens upward. A line-to-line winding defined by a line-to-line gap between axially adjacent spring wires has a line-to-line gap between the axially one-side end of the central winding portion and the outer end portion of the first end turn portion. a first change region in which the line gap increases as it progresses along the circumferential direction from the first line gap zero point where the is zero to the other side in the axial direction; and a reference region extending along the circumferential direction to the other side in the axial direction with the line gap remaining at the reference value,
The first change region ends at a position less than one turn in the circumferential direction from the zero point of the first inter-wire gap at the axial outer end toward the other axial direction side, and the inter-wire gap at the terminal end of the axial inner end. The gap is configured to be larger than the standard value,
Between the first change region and the reference region, the line-to-line distance becomes smaller as it progresses in the circumferential direction from the terminal end of the first change region toward the end of the reference region on one side in the axial direction. 3. A coil spring according to claim 1 or 2, characterized in that there is provided a first transition region where A coil spring formed by forming a spring wire into a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction,
a first end turn portion having a first bearing surface facing one side in the axial direction and extending along the circumferential direction from an outer end portion forming the first end portion toward an inner end portion on the other side in the axial direction; a second end turn portion having a second bearing surface facing the other side in the axial direction and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction; a center winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion;
from the outer end to the inner end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the While the center position of the spring wire is gradually positioned on the other side in the axial direction, the outer end portion of the first end turn portion advances from the outer end portion toward the inner end portion of the first end turn portion by half a turn. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the first end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward the other side in the axial direction from the outer end portion of the first end turn portion is a curved line that opens upward,
from the outer end to the inner end of the second end turn so that the line gap between the end of the center turn on the other side in the axial direction and the outer end of the second end turn is zero. The amount of displacement of the center position of the spring wire to one side in the axial direction between the While the center position of the spring wire is gradually positioned on one side in the axial direction, the outer end portion of the second end turn portion advances from the outer end portion toward the inner end portion of the second end turn portion by half a turn. The amount of displacement of the center position of the spring wire to one side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the second end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward one axial direction side from the outer end portion of the second end turn portion is a curve that opens downward over the entire area from the outer end to the inner end of the second end turn portion,
The coil spring, wherein the curve has a shape in which a slope of a tangent line to the curve increases from the outer end portion to the inner end portion of the second end turn portion. A coil spring formed by forming a spring wire into a helical shape from a first end on one side in the axial direction toward a second end on the other side in the axial direction,
a first end turn portion having a first bearing surface facing one side in the axial direction and extending along the circumferential direction from an outer end portion forming the first end portion toward an inner end portion on the other side in the axial direction; a second end turn portion having a second bearing surface facing the other side in the axial direction and extending along the circumferential direction from an outer end portion forming the second end portion toward an inner end portion on the one side in the axial direction; a center winding portion spirally extending along the circumferential direction from the inner end portion of the first end turn portion toward the other side in the axial direction and connected to the inner end portion of the second end turn portion;
from the outer end to the inner end of the first end turn so that the line gap between the end of the center turn on one side in the axial direction and the outer end of the first end turn is zero. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the While the center position of the spring wire is gradually positioned on the other side in the axial direction, the outer end portion of the first end turn portion advances from the outer end portion toward the inner end portion of the first end turn portion by half a turn. The amount of displacement of the center position of the spring wire to the other side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the first end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward the other side in the axial direction from the outer end portion of the first end turn portion is a curved line that opens upward,
from the outer end to the inner end of the second end turn so that the line gap between the end of the center turn on the other side in the axial direction and the outer end of the second end turn is zero. The amount of displacement of the center position of the spring wire to one side in the axial direction between the While the center position of the spring wire is gradually positioned on one side in the axial direction, the outer end portion of the second end turn portion advances from the outer end portion toward the inner end portion of the second end turn portion by half a turn. The amount of displacement of the center position of the spring wire to one side in the axial direction between the points is smaller than 1/4 of the thickness of the spring wire, and the displacement from the outer end of the second end turn portion to the inside A circumferential movement amount of the spring wire advancing along the circumferential direction toward the end portion and an axial displacement amount of the center position of the spring wire toward one axial direction side from the outer end portion of the second end turn portion A coil spring characterized in that the relationship between is a curved shape that opens downward. A line-to-line winding defined by a line-to-line gap between axially adjacent spring wires has a line-to-line gap between the axially one-side end of the central winding portion and the outer end portion of the first end turn portion. a first change region in which the line gap increases as it progresses along the circumferential direction from the first line gap zero point where the is zero to the other side in the axial direction; A reference area extending along the other side in the axial direction with the line gap remaining at the reference value, and a reference area located on the other side in the axial direction of the reference area and extending along the other side in the axial direction along the circumferential direction. a second change region ending at the second zero point of the line gap where the line gap becomes zero and the line gap becomes zero according to
The first change region ends at a position of less than one turn in the circumferential direction from the zero point of the first gap between lines at the outer end in the axial direction to the other side in the axial direction, and the gap at the end of the inner end in the axial direction is The second change region ends at a position less than one turn in the circumferential direction from the zero point of the second gap between the wires at the axial outer end to one side in the axial direction, and extends along the axial direction. The line gap at the end of the direction inner end is configured to be larger than the reference value,
Between the first change region and the reference region, the line-to-line distance becomes smaller as it progresses in the circumferential direction from the terminal end of the first change region toward the end of the reference region on one side in the axial direction. Between the second change region and the reference region, progresses in the circumferential direction from the end of the second change region toward the other end in the axial direction of the reference region 6. The coil spring according to claim 4 or 5, wherein a second transition region is provided in which the line-to-line distance becomes smaller according to the distance and becomes the reference value.

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